Metadata Report for BODC Series Reference Number 1097124


Metadata Summary

Data Description

Data Category Multiple data types -ship
Instrument Type
NameCategories
Sea-Bird SBE 19plus SEACAT CTD  CTD; water temperature sensor; salinity sensor
WETLabs WETStar fluorometer  fluorometers
WETLabs ECO-VSF Optical Backscatter Meter  optical backscatter sensors
WETLabs ac-9 Absorption and Attenuation meter  transmissometers
Instrument Mounting research vessel
Originating Country United States
Originator Dr Barney Balch
Originating Organization Bigelow Laboratory for Ocean Sciences
Processing Status banked
Project(s) Atlantic Meridional Transect Phase2(AMT)
 

Data Identifiers

Originator's Identifier AMT19-MERGED-SAS-FLOW-AC9.MAT
BODC Series Reference 1097124
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2009-10-12 12:10
End Time (yyyy-mm-dd hh:mm) 2009-11-28 10:33
Nominal Cycle Interval 10.0 seconds
 

Spatial Co-ordinates

Start Latitude 50.15650 N ( 50° 9.4' N )
End Latitude 46.56770 S ( 46° 34.1' S )
Start Longitude 5.05820 W ( 5° 3.5' W )
End Longitude 55.74470 W ( 55° 44.7' W )
Positional Uncertainty 0.0 to 0.01 n.miles
Minimum Sensor Depth 5.0 m
Maximum Sensor Depth 5.0 m
Minimum Sensor Height -
Maximum Sensor Height -
Sea Floor Depth -
Sensor Distribution Fixed common depth - All sensors are grouped effectively at the same depth which is effectively fixed for the duration of the series
Sensor Depth Datum Approximate - Depth is only approximate
Sea Floor Depth Datum -
 

Parameters

BODC CODE Rank Units Short Title Title
LAMBIN01 0 Nanometres Wavelength Wavelength of electromagnetic radiation measurement
AADYAA01 1 Days Date(Loch_Day) Date (time from 00:00 01/01/1760 to 00:00 UT on day)
AAFDZZ01 1 Days Time(Day_Fract) Time (time between 00:00 UT and timestamp)
ACYCAA01 1 Dimensionless Record_No Sequence number
ALATGP01 1 Degrees Lat_GPS Latitude north (WGS84) by unspecified GPS system
ALONGP01 1 Degrees Lon_GPS Longitude east (WGS84) by unspecified GPS system
BS532VSF 1 per metre attn_backscat_532nm Attenuation due to backscatter (532nm wavelength) in the water body by scattering photometer and calibration to read zero in clear water with computation from volume scatter data
CPHLUT01 1 Milligrams per cubic metre chl-a_water_NTTFfluor_sampcal Concentration of chlorophyll-a {chl-a CAS 479-61-8} per unit volume of the water body [particulate >unknown phase] by through-flow fluorometer plumbed into non-toxic supply and calibration against sample data
PSALSU01 1 Dimensionless P_sal_TSG_uncalib Practical salinity of the water body by thermosalinograph and computation using UNESCO 1983 algorithm and NO calibration against independent measurements
TEMPSU01 1 Degrees Celsius UncalTSGTmp Temperature of the water body by thermosalinograph and NO verification against independent measurements
ABSPXAC9 2 per metre absorb_cwoffset_2D Absorbance of electromagnetic radiation (unspecified single wavelength) {light absorbance} by the water body by transmissometer and calibration to read zero in clear water
ABSULT01 2 per metre absorb_lt0_2um Absorbance of electromagnetic radiation (unspecified single wavelength) {light absorbance} per unit length of the water body [dissolved plus reactive particulate <0.2um phase] by transmissometer and calibration to read zero in clear water
ATTNXAC9 2 per metre attn_cwoffset_2D Attenuation (unspecified single wavelength) per unit length of the water body by transmissometer and calibration to read zero in clear water
 

Definition of Rank

  • Rank 1 is a one-dimensional parameter
  • Rank 2 is a two-dimensional parameter
  • Rank 0 is a one-dimensional parameter describing the second dimension of a two-dimensional parameter (e.g. bin depths for moored ADCP data)

Problem Reports

No Problem Report Found in the Database

AMT19 flow-through bio-optical Data Quality document

Data Quality Report

On the whole the data provided were of good quality. Some isolated data points were converted to the absent data value and flagged accordingly where the values were not considered within a reasonable range for the parameters. There were short periods on a few days where all data from TEMPSU01, PSALSU01, CPHLUT01 and BS532VSF have been flagged suspect. The data values have not been changed but users should apply their discretion when using these data. These periods occur in the afternoon about the time of the solar noon station. It is possible ship's non-toxic supply has been affected by the use of the ship's thrusters used to keep the ship on station introducing bubbles into the water pumped through the system.

During screening procedures, several periods were identified with gaps on the data.


Data Access Policy

Open Data supplied by Natural Environment Research Council (NERC)

You must always use the following attribution statement to acknowledge the source of the information: "Contains data supplied by Natural Environment Research Council."


Narrative Documents

Sea-Bird SBE 19 and SBE 19plus SEACAT Profiler CTDs

The SBE 19 SEACAT Profiler is a self-contained, battery powered, pumped CTD system designed to measure conductivity, temperature, and pressure in marine or fresh water environments to depths of 10,500 meters. It was replaced by the SBE 19 plus model in 2001. An updated version of this instrument is the SBE 19 plus V2, which incorporates an electronics upgrade and additional features, with six differentially amplified A/D input channels, one RS-232 data input channel, and 64 MB FLASH memory.

The standard CTD unit comes with a plastic housing (rated to 600 m), although this can be replaced by titanium housing for depths up to 7000 m. It is typically used for CTD profiling although a conversion kit is available for mooring deployments. The CTD can also be attached to an SBE 36 CTD Deck Unit and Power/Data Interface Module (PDIM) for real-time operation on single-core armored cable up to 10,000 m.

Specifications

Parameter SBE 19 SBE 19 plus
Temperature

Range: -5 to +35 °C

Accuracy: 0.01 °C

Resolution: 0.001 °C

Calibration: +1 to +32 °C*

Range: -5 to +35 °C

Accuracy: 0.005 °C

Resolution: 0.0001 °C

Calibration: +1 to +32 °C*

Conductivity

Range: 0 to 7 S m -1 (0 to 70 mmho cm -1 )

Accuracy: 0.001 S m -1

Resolution: 0.0001 S m -1

Calibration: 0 to 7 S m -1 . Physical calibration over the range 1.4 - 6 S m -1 *

Range: 0 to 9 Sm -1

Accuracy: 0.0005

Resolution: 0.00005 (most oceanic waters, resolves 0.4 ppm in salinity); 0.00007 (high salinity waters, resolves 0.4 ppm in salinity); 0.00001 (fresh waters, resolves 0.1 ppm in salinity)

Calibration: 0 to 9 S m -1 . Physical calibration over the range 1.4 - 6 S m -1 *

Strain gauge pressure sensor

Range: 0 to100, 150, 300, 500, 1000, 1500, 3000, 5000, 10000 or 15000 psia

Accuracy: 0.25% of full scale range (100 - 1500 psia); 0.15% of full scale range (3000 - 15000 psia)

Resolution: 0.015% of full scale

Calibration: 0 to full scale in 20% steps

Range: 0 to 20, 100, 350, 1000, 2000, 3500 or 7000 m

Accuracy: 0.1% of full scale range

Resolution: 0.002% of full scale range

Calibration: ambient pressure to full scale range in 5 steps

*Measurements outside this range may be at slightly reduced accuracy due to extrapolation errors.

Options and accessories

Additional sensors can be attached to the CTD, including:

The standard SBE 5M pump may be replaced by an SBE 5P (plastic housing) or 5T (titanium housing) pump for use with dissolved oxygen and/or other pumped sensors. Further details can be found in the manufacturer's SBE 19 plus V2 instrument specification or the SBE 19 and SBE 19 plus user guides.

WET Labs WETStar Fluorometers

WET Labs WETStar fluorometers are miniature flow-through fluorometers, designed to measure relative concentrations of chlorophyll, CDOM, uranine, rhodamineWT dye, or phycoerythrin pigment in a sample of water. The sample is pumped through a quartz tube, and excited by a light source tuned to the fluorescence characteristics of the object substance. A photodiode detector measures the portion of the excitation energy that is emitted as fluorescence.

Specifications

By model:

  Chlorophyll WETStar CDOM WETStar Uranine WETStar Rhodamine WETStar Phycoerythrin WETStar
Excitation wavelength 460 nm 370 nm 485 nm 470 nm 525 nm
Emission wavelength 695 nm 460 nm 530 nm 590 nm 575 nm
Sensitivity 0.03 µg l -1 0.100 ppb QSD 1 µg l -1 - -
Range 0.03-75 µg l -1 0-100 ppb; 0-250 ppb 0-4000 µg l -1 - -

All models:

Temperature range 0-30°C
Depth rating 600 m
Response time 0.17 s analogue; 0.125 s digital
Output 0-5 VDC analogue; 0-4095 counts digital

Further details can be found in the manufacturer's specification sheet , and in the instrument manual .

WETLabs ECO-VSF Optical Backscatter Meter

The ECO-VSF is a scattering meter designed to measure the angular distribution of scattered radiation of the backward hemisphere. The instrument measures optical scattering at three angles (100°, 125° and 150°), providing the shape of the Volume Scattering Function (VSF) throughout the backscattering region. Interpolation and extrapolation are used to determine scattering at intermediate angles. It also provides the total backscatter coefficient between 90° and 180° by integration and extrapolation.

The ECO-VSF comes in five versions, with a variety of power options, sampling strategies and anti-fouling capabilities:

The specifications below are common to all versions.

Specifications

Wavelength 470, 532 or 660 nm
Sensitivity 1.24x10 -5
Typical range ~ 0.0012-5 m -1
Linearity 99 % R 2
Temperature range 0-30°
Depth rating 600 m (standard)
Sample rate up to 8 Hz
Pressure sensor optional
Temperature sensor optional

Further details can be found in the manufacturer's specification sheet .

WETLabs ac-9 and ac-s Spectral Absorption and Attenuation Meters

The WETLabs ac-9 and ac-s meters measure the spectral transmittance and spectral absorption of water, allowing determination of absorption and beam attenuation coefficients. The instruments incorporate a flow-through system and a dual path configuration that permits concurrent measurement of both coefficients along a 25 cm path. The ac-9 provides measurements at nine wavelengths in the range 412-715 nm, whereas the ac-s provides measurements at >80 wavelengths from 400-730 nm.

Specifications

Parameters ac-9 ac-s
Temperature range 0-30 ° 0-30 °
Rated depth 500 or 5000 m 500 m
Spectral range 412-715 nm 400-730 nm
Band-pass 10 nm per channel 15 nm per channel
Pathlength 25 cm (optional 10 cm) 25 cm (optional 10 cm)
Beam cross-section 8 mm dia. (nominal) 8 mm dia. (nominal)
Linearity >=99 % R 2 >=99 % R 2
Wavelength output 9 80-90 in 4 nm steps
Accuracy ±0.01 m -1 ±0.01 m -1
Dynamic range 0.001-10 m -1 0.001-10 m -1

Further details can be found in the manufacturer's specification sheet .

AMT19 flow-through bio-optical Instrumentation Description

The instruments used to collect the underway data were:

AMT19 flow-through bio-optical Processing

BODC Data Processing Procedures

A file was submitted to BODC containing data from MicroSAS radiometer merged with underway data. The archived file was given the BODC's accession number BGL100197, which includes two different dataset IDs (one for the radiometer parameters and the other for the underway data). The following parameters were supplied for the underway measurements: temperature, salinity, chlorophyll-a, backscattering coefficient, absorption and attenuation coefficients'. Additional metadata was provided, and these included date, time, latitude and longitude obtained through the ship's GPS stream.

No unit conversions were necessary as all the parameters were provided in the same units as in the BODC Parameter Dictionary.

A parameter mapping table is provided below;

Originator's Parameter Description Units BODC Parameter Code Description Units Comments
lat Latitude, as mentioned on the originator's file degrees ALATGP01 Latitude north (WGS84) by unspecified GPS system Global Positioning System (receiver type unspecified) degrees -
lon Longitude, as mentioned on the originator's file degrees ALONGP01 Longitude east (WGS84) by unspecified GPS system Global Positioning System (receiver type unspecified) degrees -
bbp532 Backscattering coefficient of particles(*) m -1 BS532VSF Attenuance due to backscatter (532nm wavelength) in the water body by scattering photometer and calibration to read zero in clear water with computation from volume scatter data m -1 NA
agp Absorption Coefficient of Gelbstoff + particles(*) m -1 ABSPXAC9 Light absorbance (unspecified single wavelength) by the water body by transmissometer and calibration to read zero in clear water m -1 NA
ag Absorption Coefficient of Gelbstoff(*) m -1 ABSULT01 Light absorbance (unspecified single wavelength) per unit length of the water body dissolved plus reactive particulate <0.2 µm by transmissometer and calibration to read zero in clear water m -1 NA
cgp Absorption Coefficient of Gelbstoff + particles(*) m -1 ATTNXAC9 Attenuance (unspecified single wavelength) per unit length of the water body by transmissometer and calibration to read zero in clear water m -1 NA
wavelength Wavelength(*) nm LAMBIN01 Wavelength of electromagnetic radiation measurement nm NA
Sal Salinity - PSALSU01 Practical salinity of the water body by thermosalinograph and computation using UNESCO 1983 algorithm and NO calibration against independent measurements - NA
Temp Water temperature degrees Celsius TEMPSU01 Temperature of the water body by thermosalinograph and NO verification against independent measurements degrees Celsius NA
Chl Fluorometrically/spectrophotometrically-derived chlorophyll a(*) mg m -3 CPHLUT01 Concentration of chlorophyll-a {chl-a} per unit volume of the water body [particulate phase] by through-flow fluorometer plumbed into non-toxic supply and calibration against sample data mg m -3 NA

Parameters' marked with (*) are described on the following link: Standardized Field Names and Units for SeaBASS files

AMT19 flow-through bio-optical data

Originator's Protocol for Data Acquisition and Analysis

The underway system operated semi-continuously with water from the ship's non-toxic supply at a rate of 4 L min -1 . Every five to seven minutes the following parameters were measured: temperature, salinity, chlorophyll fluorescence and total backscattering at 532 nm. Every two minutes absorption and attenuation coefficients were measured at nine different wavelengths on unfiltered and 0.2 µm filtered water.

The TSG used the manufacturer's calibrations to produce salinity and temperature. The fluorometer was calibrated using discrete chlorophyll measurements made from the non-toxic supply and the surface CTD bottle samples.

References Cited

N/A


Project Information

The Atlantic Meridional Transect - Phase 2 (2002-2006)

Who was involved in the project?

The Atlantic Meridional Transect Phase 2 was designed by and implemented by a number of UK research centres and universities. The programme was hosted by Plymouth Marine Laboratory in collaboration with the National Oceanography Centre, Southampton. The universities involved were:

What was the project about?

AMT began in 1995, with scientific aims to assess mesoscale to basin scale phytoplankton processes, the functional interpretation of bio-optical signatures and the seasonal, regional and latitudinal variations in mesozooplankton dynamics. In 2002, when the programme restarted, the scientific aims were broadened to address a suite of cross-disciplinary questions concerning ocean plankton ecology and biogeochemistry and the links to atmospheric processes.

The objectives included the determination of:

The data were collected with the aim of being distributed for use in the development of models to describe the interactions between the global climate system and ocean biogeochemistry.

When was the project active?

The second phase of funding allowed the project to continue for the period 2002 to 2006 and consisted of six research cruises. The first phase of the AMT programme ran from 1995 to 2000.

Brief summary of the project fieldwork/data

The fieldwork on the first three cruises was carried out along transects from the UK to the Falkland Islands in September and from the Falkland Islands to the UK in April. The last three cruises followed a cruise track between the UK and South Africa, only deviating from the traditional transect in the southern hemisphere. During this phase the research cruises sampled further into the centre of the North and South Atlantic Ocean and also along the north-west coast of Africa where upwelled nutrient rich water is known to provide a significant source of climatically important gases.

Who funded the project?

Natural Environment Research Council (NERC)


Data Activity or Cruise Information

Cruise

Cruise Name JC039 (AMT19, JC040)
Departure Date 2009-10-13
Arrival Date 2009-12-01
Principal Scientist(s)Andrew Rees (Plymouth Marine Laboratory)
Ship RRS James Cook

Complete Cruise Metadata Report is available here


Fixed Station Information


No Fixed Station Information held for the Series


BODC Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:

Flag Description
Blank Unqualified
< Below detection limit
> In excess of quoted value
A Taxonomic flag for affinis (aff.)
B Beginning of CTD Down/Up Cast
C Taxonomic flag for confer (cf.)
D Thermometric depth
E End of CTD Down/Up Cast
G Non-taxonomic biological characteristic uncertainty
H Extrapolated value
I Taxonomic flag for single species (sp.)
K Improbable value - unknown quality control source
L Improbable value - originator's quality control
M Improbable value - BODC quality control
N Null value
O Improbable value - user quality control
P Trace/calm
Q Indeterminate
R Replacement value
S Estimated value
T Interpolated value
U Uncalibrated
W Control value
X Excessive difference

SeaDataNet Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:

Flag Description
0 no quality control
1 good value
2 probably good value
3 probably bad value
4 bad value
5 changed value
6 value below detection
7 value in excess
8 interpolated value
9 missing value
A value phenomenon uncertain